Structural Characterization of a Series of N5-Ligated Mn<sup>IV</sup>-Oxo Species

Massie, Allyssa A.; Denler, Melissa C.; Singh, Reena; Sinha, Arup; Nordlander, Ebbe; Jackson, Timothy A.

Structural Characterization of a Series of N5-Ligated Mn^IV-Oxo Species

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Massie, Allyssa A. ; Denler, Melissa C. ; Singh, Reena ^LU ; Sinha, Arup ^LU ; Nordlander, Ebbe ^LU and Jackson, Timothy A. (2020) In Chemistry - A European Journal 26(4). p.900-912

Abstract: Analysis of extended X-ray absorption fine structure (EXAFS) data for the Mn^IV-oxo complexes [Mn^IV(O)(^DMMN4py)]²⁺, [Mn^IV(O)(2pyN2B)]²⁺, and [Mn^IV(O)(2pyN2Q)]²⁺ (^DMMN4py=N,N-bis(4-methoxy-3,5-dimethyl-2-pyridylmethyl)-N-bis(2-pyridyl)methylamine; 2pyN2B=(N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine, and 2pyN2Q=N,N-bis(2-pyridyl)-N,N-bis(2-quinolylmethyl)methanamine) afforded Mn=O and Mn−N bond lengths. The Mn=O distances for [Mn^IV(O)(^DMMN4py)]²⁺ and [Mn^IV(O)(2pyN2B)]²⁺ are 1.72 and 1.70 Å, respectively. In contrast, the Mn=O distance for... (More); Analysis of extended X-ray absorption fine structure (EXAFS) data for the Mn^IV-oxo complexes [Mn^IV(O)(^DMMN4py)]²⁺, [Mn^IV(O)(2pyN2B)]²⁺, and [Mn^IV(O)(2pyN2Q)]²⁺ (^DMMN4py=N,N-bis(4-methoxy-3,5-dimethyl-2-pyridylmethyl)-N-bis(2-pyridyl)methylamine; 2pyN2B=(N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine, and 2pyN2Q=N,N-bis(2-pyridyl)-N,N-bis(2-quinolylmethyl)methanamine) afforded Mn=O and Mn−N bond lengths. The Mn=O distances for [Mn^IV(O)(^DMMN4py)]²⁺ and [Mn^IV(O)(2pyN2B)]²⁺ are 1.72 and 1.70 Å, respectively. In contrast, the Mn=O distance for [Mn^IV(O)(2pyN2Q)]²⁺ was significantly longer (1.76 Å). We attribute this long distance to sample heterogeneity, which is reasonable given the reduced stability of [Mn^IV(O)(2pyN2Q)]²⁺. The Mn=O distances for [Mn^IV(O)(^DMMN4py)]²⁺ and [Mn^IV(O)(2pyN2B)]²⁺ could only be well-reproduced using DFT-derived models that included strong hydrogen-bonds between second-sphere solvent 2,2,2-trifluoroethanol molecules and the oxo ligand. These results suggest an important role for the 2,2,2-trifluoroethanol solvent in stabilizing Mn^IV-oxo adducts. The DFT methods were extended to investigate the structure of the putative [Mn^IV(O)(N4py)]²⁺⋅(HOTf)₂ adduct. These computations suggest that a Mn^IV-hydroxo species is most consistent with the available experimental data.
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Please use this url to cite or link to this publication: https://lup.lub.lu.se/record/7ae4edb5-c845-43cc-9fb6-899419f763c5

author

Massie, Allyssa A. ; Denler, Melissa C. ; Singh, Reena ^LU ; Sinha, Arup ^LU ; Nordlander, Ebbe ^LU and Jackson, Timothy A.

organization

Chemical Physics

publishing date

2020-01-16

type

Contribution to journal

publication status

published

subject

Theoretical Chemistry

keywords

DFT calculations, electronic structure, oxido ligands, spectroscopy, X-ray absorption spectroscopy

in

Chemistry - A European Journal

volume

26

issue

4

pages

13 pages

publisher

Wiley-Blackwell

external identifiers

scopus:85076723841
pmid:31693757

ISSN

0947-6539

DOI

10.1002/chem.201904434

language

English

LU publication?

yes

id

7ae4edb5-c845-43cc-9fb6-899419f763c5

date added to LUP

2020-01-10 12:03:02

date last changed

2024-03-20 02:31:12

@article{7ae4edb5-c845-43cc-9fb6-899419f763c5,
  abstract     = {{<p>Analysis of extended X-ray absorption fine structure (EXAFS) data for the Mn<sup>IV</sup>-oxo complexes [Mn<sup>IV</sup>(O)(<sup>DMM</sup>N4py)]<sup>2+</sup>, [Mn<sup>IV</sup>(O)(2pyN2B)]<sup>2+</sup>, and [Mn<sup>IV</sup>(O)(2pyN2Q)]<sup>2+</sup> (<sup>DMM</sup>N4py=N,N-bis(4-methoxy-3,5-dimethyl-2-pyridylmethyl)-N-bis(2-pyridyl)methylamine; 2pyN2B=(N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine, and 2pyN2Q=N,N-bis(2-pyridyl)-N,N-bis(2-quinolylmethyl)methanamine) afforded Mn=O and Mn−N bond lengths. The Mn=O distances for [Mn<sup>IV</sup>(O)(<sup>DMM</sup>N4py)]<sup>2+</sup> and [Mn<sup>IV</sup>(O)(2pyN2B)]<sup>2+</sup> are 1.72 and 1.70 Å, respectively. In contrast, the Mn=O distance for [Mn<sup>IV</sup>(O)(2pyN2Q)]<sup>2+</sup> was significantly longer (1.76 Å). We attribute this long distance to sample heterogeneity, which is reasonable given the reduced stability of [Mn<sup>IV</sup>(O)(2pyN2Q)]<sup>2+</sup>. The Mn=O distances for [Mn<sup>IV</sup>(O)(<sup>DMM</sup>N4py)]<sup>2+</sup> and [Mn<sup>IV</sup>(O)(2pyN2B)]<sup>2+</sup> could only be well-reproduced using DFT-derived models that included strong hydrogen-bonds between second-sphere solvent 2,2,2-trifluoroethanol molecules and the oxo ligand. These results suggest an important role for the 2,2,2-trifluoroethanol solvent in stabilizing Mn<sup>IV</sup>-oxo adducts. The DFT methods were extended to investigate the structure of the putative [Mn<sup>IV</sup>(O)(N4py)]<sup>2+</sup>⋅(HOTf)<sub>2</sub> adduct. These computations suggest that a Mn<sup>IV</sup>-hydroxo species is most consistent with the available experimental data.</p>}},
  author       = {{Massie, Allyssa A. and Denler, Melissa C. and Singh, Reena and Sinha, Arup and Nordlander, Ebbe and Jackson, Timothy A.}},
  issn         = {{0947-6539}},
  keywords     = {{DFT calculations; electronic structure; oxido ligands; spectroscopy; X-ray absorption spectroscopy}},
  language     = {{eng}},
  month        = {{01}},
  number       = {{4}},
  pages        = {{900--912}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{Chemistry - A European Journal}},
  title        = {{Structural Characterization of a Series of N5-Ligated Mn<sup>IV</sup>-Oxo Species}},
  url          = {{http://dx.doi.org/10.1002/chem.201904434}},
  doi          = {{10.1002/chem.201904434}},
  volume       = {{26}},
  year         = {{2020}},
}

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Structural Characterization of a Series of N5-Ligated Mn^IV-Oxo Species